Uri Blass wrote:
The information that I can provide is that
Strelka1.8 is designed to be as similiar as possible to rybka1 beta.
There are positions when they have the same fail high and fail low and when I analyze blocked positions I get almost the same data(evaluation may be different by 0.01 pawns or something like that but they have the same fail high and fail low when the only difference is that free source strelka needs to get depth that is bigger by 2 plies).

strelka1.8 and Rybka1 beta even share the same bug that no program that I know has(not a bug that fruit has).

Uri

Using Don's similarity test, Strelka 1.8 is closer to Rybka 1.0 than the statistical noise, therefore Strelka 1.8 is an exact clone of Rybka 1.0 within error margins.

In the graph, the distance to the common ancestor denotes the degree of relatedness.

Also, Rybka 1.0 seems more related to Fruit 2.1 than Ippo family and Houdini are to Rybka 3.

Oh come on please! I find it hard to believe that Vas could create a new number one chess engine from the ground up without ANY reference material at all. What the hell is he a Chess Programing GOD? We are talking about 4 number one chess engines back to back.

Chan Rasjid wrote:It seems derivative under GPL is not only about 'cut_and_paste', but includes translation of the source code (including in a different computer language). So Strelka translating Fruit to bitboard has a legal issue if not GPL'ed. Any other program getting too close to Strelka could also legally be a derivative.

Not so. "Translating" Fruit to bitboards is NOT a translation in the sense of copyright law. For that, only translations that merely replace the variable names, or replace {} and = by BEGIN, END and := to turn C into Pascal, and such. Bitboards are other data-structures, and are manipulated by other statements, which are not 1 to 1 corresponding to the statements that manipulate a mailbox board. That the high-level meaning is equivalent, because they both represent Chess positions, and that the high-levelfunction of a bitboard MakeMove is fully equivalent to a mailbox MakeMove is not enugh to qualify it as a translation of the code. It makes it a translation of the algorithms, of course. But algorithms are not protected by copyrights in the first place, let alone their translations.

Fabien Letouzey wrote:The short answer was "no", it was not a verbatim copy of the source code. All the code had been typed (can't say "designed" though, see below) by an individual. So legally there was no issue that I knew of. It was however a whole re-write (copy with different words if you like, similar to a translation) of the algorithms. Not just an extraction of a couple of ideas as is common, and normal.

Well, that is not a violation of the GPL, well? So why do you think it is of any relevance whatsoever?

And it still does not say anything that anyone wih eyes could not have known for years...

First, I won't stress enough that I really dislike it when people throw mud at each-others. So up to now I never took part at the Rybka<>Fruit debate.

But I'm a jurist and I teach law, so after what Fabien said there are now some things that bother me. And what GPL is is irrelevent according to most of national laws. And as Fabien is french I can testify that there are plenty of legal tools available to him. Some of them are probably in most western legal arsenals actually. One of them is called "parasitisme", and it punishes people who generate wealth out of someone else's work without his authorization. And this is just an example.

Now, and that's also why I didn't want to be part of this debate, my jurist DNA makes me consider people as being innocent until proven guilty. So my opinion is that Vas should settle this once and for all by sending his close code for comparison with Fruit to a respected authority of our small community (of course this person will have to keep this code private and not make use of it for other projects). Some names : Jim Ablett, Dann Corbit, Robert Hyatt. Maybe Ed Shröder too, as he's experienced, respected and retired from business.

Last edited by JuLieN on Mon Jan 24, 2011 11:26 am, edited 1 time in total.

AdminX wrote:Oh come on please! I find it hard to believe that Vas could create a new number one chess engine from the ground up without ANY reference material at all. What the hell is he a Chess Programing GOD? We are talking about 4 number one chess engines back to back.

You've probably never written a Chess engine yourself. All authors periodically start to rewrite completely from scratch. Because as you are progressing, it aways turns out that you have painted yourself into a corner in many places with your old code, and in view of the progression of nowledge, that corner does not look soattractive anymore as it once did...

JuLieN wrote:
But I'm a jurist and I teach law, so after what Fabien said there are now some things that bother me. And what GPL is is irrelevent according to most of national laws. And as Fabien is french I can testify that there are plenty of legal tools available to him.

You are right in that the GPL is somewhat irrelevant. Either you follow the GPL, or you commit a copyright violation. The first clearly didn't happen, so the second applies, and the exact results depend on local laws (which are somewhat universal due to agreements between countries).

BTW. It was claimed a while ago that Fruit copyright was assigned to the FSF. They would likely have registered copyright, which has grave consequences regarding damages available.

One of them is called "parasitisme", and it punishes people who generate wealth out of someone else's work without his authorization.

If you claim to be versed in the legal profession, can you be more specific? Don't tell me it's illegal to build on the work of others in France. Surely there's more to it than that. We are a smart crowd and would appreciate a good explanation from an expert.

AdminX wrote:Oh come on please! I find it hard to believe that Vas could create a new number one chess engine from the ground up without ANY reference material at all. What the hell is he a Chess Programing GOD? We are talking about 4 number one chess engines back to back.

You've probably never written a Chess engine yourself. All authors periodically start to rewrite completely from scratch.

I will just cut out your personal attack and cut to the chase. No I have not written a chess program myself, not in C anyway. It was more like Basic (not a chess engine) and that was a very long time ago. Yes, Programers do start from scratch from time to time, However how many do you know that create a New number 1 in such a short time frame from nothing at all?

Last edited by AdminX on Mon Jan 24, 2011 11:40 am, edited 1 time in total.

JuLieN wrote:But I'm a jurist and I teach law, so after what Fabien said there are now some things that bother me. And what GPL is is irrelevent according to most of national laws. And as Fabien is french I can testify that there are plenty of legal tools available to him. Some of them are probably in most western legal arsenals actually. One of them is called "parasitisme", and it punishes people who generate wealth out of someone else's work without his authorization. And this is just an example.

Sorry, I am not a jurist at all, but I feel confident enough to challenge you on the highlighted quote. Most national laws respect agreements between individuals. And that is exactly what the GPL is: a very elaborate and precise agreement of what others are allowed to do with your code and what not. Without having to seek explicit authorization. The release under GPL is the authorization. You would be steamrollered in court...

One of them is called "parasitisme", and it punishes people who generate wealth out of someone else's work without his authorization.

If you claim to be versed in the legal profession, can you be more specific? Don't tell me it's illegal to build on the work of others in France. Surely there's more to it than that. We are a smart crowd and would appreciate a good explanation from an expert.

I could make a legal consult for you as soon as we discuss the price.

Just kidding. Well I'm not a specialist of international laws, so what I can say merely regards french law (but Fabien is french, so as far as FSF isn't concerned that might be the one that matters here), but I'm pretty confident that business law is more or less pretty unified in the western world (especially in Europe, because of the economical treaties).

In french law, we first have the concept of "concurrence déloyale" (Unfair business practices), but this only involves companies (or people) in a business competition. Here, Fruit is free and Rybka isn't, so they're not in a business competition. But we also have the concept of "parasitisme" (parasitism). This last one doesn't come from the law but from the tribunals practice : the magistrates consider that if someone takes advantage of someone else's work to make profit without this person agreeing to that and receiving a share of the profit then it's unfair and must be punished. What you must understand is that it's a general concept that gives the judges a big freedom. For instance, it has also been considered "parasistism" for a website to include famous names/brands in its metadata to gather more traffic that it otherwise would. I think you get the picture.

Last edited by JuLieN on Mon Jan 24, 2011 11:48 am, edited 1 time in total.